A coupler is one of important components of a car and has a standard connection contour, and the main functions thereof are to ensure coupling between cars and to realize train marshalling so as to draw the car.
Conventional coupler of the car generally has three operating states, i.e., locking state, uncoupling state and full open state, which are also referred to as three states. When a coupler is in the locking state, a coupler lock stops a coupler knuckle from being opened so that coupled cars wouldn't be disengaged spontaneously. When rotating an uncoupling lever, the coupler lock is pushed to an uncoupling position under an upward movement of a bottom locklift connector coupled with an uncoupling lever and a bottom locklift toggle. At this moment, the coupler is switched into the uncoupling state, and cars are disengaged when the coupler knuckle is opened under an external force. When lifting the uncoupling lever to a highest position, the coupler knuckle is pushed to the full open position under the action of the coupler knuckle thrower so that the coupler is switched into the full open state, and adjacent cars may be coupled. Two cars can be coupled with each other by themselves when they are colliding, and disengagement between coupled cars can be achieved by operating the uncoupling lever from outside. In this way, the operating efficiency of train marshalling can be increased and safety of operators can be ensured. Referring to FIG. 1, a schematic view of an existing 13-type bottom operating coupler in a use state is shown.
In hump shunting operation (seeing FIGS. 2a and 2b), an operator standing at the side of railroad line having signal display operates an uncoupling lever such that a back coupler of a humping car is in the uncoupling state. During humping, on the one hand, a speed reducer on the humping line will reduce humping speed of the humping car so as to ensure that the humping car would not exceed an allowable speed when being shunted and coupled; on the other hand, the humping car will collide with a standing car when they are to be coupled. Thus, under an inertia force of the humping car, a coupler knuckle of the back coupler of the humping car is likely returned towards the locking position around a coupler knuckle pin. In other words, the back coupler is in a non-full open position or in the locking position. However, at this time, a front coupler of a subsequent humping car is in the locking position. Therefore, the previous humping car cannot be successfully coupled with the subsequent humping car after the subsequent humping car runs downwardly, thereby reducing success rate of coupling in marshalling. As a result, the operation efficiency in marshalling is affected and the safety of operators is also affected.
In view of the above disadvantages, there is an urgent demand to develop a double-side operating coupler which is applicable to many operating conditions of train marshalling such as hump shunting.